The present invention relates to a digital recording and reproducing device of a rotary head type (referred to as DAT recorder, hereinafter) and, particularly, to such device in which a cassette is loaded thereto by using the so-called slot-in mechanism and which is equipped with a mechanism for reliably holding the cassette therein during a time for which the device is not operated so that dust or the like is prevented from invading thereinto.
An outer configuration and an inner construction of a cassette for use in such DAT recorder have been standardized. FIGS. 1A and 1B show, in perspective, a top and a bottom of such cassette, respectively. In FIGS. 1A and 1B, the cassette 10 comprises a lower shell 101, an upper shell 102, a slider 103, mounted on the lower shell 101 slidably therealong, a lid 104 for exposing a magnetic tape in the cassette when the slider 103 is retracted, a loading grip 105 for holding the cassette in desired positions in the DAT device, a pair of notches 106 for unlocking a pair of slider locks 113 to allow the slider 103 to be retracted when the cassette is inserted into the DAT device, and a pair of notches 107 for retracting the slider 103 when the cassette is inserted correctly. A pair of holes 108 are provided in a bottom rear surface of the lower shell 101 for identification of the cassette and a hole 109 is also formed in the bottom rear surface of the lower shell 101 for preventing the erroneous erasure of the contents of the tape memory. A pair of data holes 110 are provided as shown.
A pair of hub holes 111 are provided in a middle portion of the lower shell 101 which are usually covered by the slider 103 having corresponding hub holes which, when the slider 103 is retracted, overlap with the hub holes 111 to allow tape reels in the cassette to be engaged with reel shafts of the DAT device, respectively. The movement of the slider 103 is usually prevented by the slider locks 113 as mentioned above.
The cassette further comprises a lid lock 112 formed on an upper face of a front end of the slider 103 for restricting the motion of the lid 104.
The lid 104 is hinged to the upper shell 102 and kicked up by a pin 14 or the like from a position shown by dotted line in FIG. 2A to that shown in FIG. 2B after the slider 103 is retracted, to provide an opening at a front end of the cassette through which the magnetic tape therein can contact with a rotary head of the DAT device.
That is, in order to open the lid 104, the cassette 10 in a position i has to be moved to a position ii and lowered with respect to the pin 14 provided stationarily in the DAT device, as shown in FIG. 3, or vice versa. Therefore, after the cassette 10 is inserted into the DAT device along a horizontal plane through a slot 20 in a front wall of the DAT device which is covered by a hinge cover 40 and passes through the position ii, it is usually lowered to open the lid and to receive the reel shafts 60 in the hub holes 111, so that the magnetic tape 113 can be in contact with the rotary head 51 mounted on a cylinder 50 as shown. Alternatively, it is possible to move an associated mechanism including the cylinder 50 of the DAT device upwardly to the cassette which is supported stationarily in the DAT device. In the latter case, however, the mechanical structure may become more complicated.
In the following description, positions i, ii and iii of the cassette 10 in the DAT device, shown in FIG. 3, are defined as an ejection position, an unloaded position in which a driving connection of the DAT device with the cassette 10 is not established while the lid 104 thereof is kept closed, and a loaded position in which a recording or reproducing operation of the DAT device is to be performed, respectively, for simplicity of description.
When the recording or reproducing operation of the DAT device is stopped for some reason while the cassette is held in the loaded position iii, the cassette is usually kept in that position as it is. This may provide no problem so long as the DAT device is stationary. However, when the DAT device is of a portable type or is mounted on a vehicle, it may be subjected to externally produced vibrations under which the tension of the magnetic tape of the cassette in the loaded position is varied, causing a breakage or a looping thereof which leads to a tangling of the tape. Further, in the loaded position in which the lid of the cassette is opened, dust may enter through the opening into the cassette. Such dust on the tape and/or the rotary head may degrade the operational performance of the DAT device for high density recording and reproducing, considerably. Therefore, the cassette should be held in the DAT device with the lid of the cassette and the slot cover of the DAT device being kept closed.